The present invention relates to medical devices. More particularly, the invention relates to a retrieval system for removing an implantable medical device from a patient blood vessel.
Filtering devices that are percutaneously placed in the vena cava have been available for over thirty years. A need for filtering devices arises in trauma patients, orthopedic surgery patients, neurosurgery patients, or in patients having medical conditions requiring bed rest or non-movement. During such medical conditions, the need for filtering devices arises due to the likelihood of thrombosis in the peripheral vasculature of patients wherein thrombi break away from the vessel wall, risking downstream embolism or embolization. Typically, filtering devices are permanent implants, each of which remains implanted in the patient for life, even though the condition or medical problem that required the device has passed. In more recent years, filters have been used or considered in preoperative patients and in patients predisposed to thrombosis which places the patient at risk for pulmonary embolism.
However, there are instances in which retrieval of the filter from the vena cava of a patient is desirable. For example, filtering may no longer be necessary, the filter may interfere with subsequent medical procedures, or the filter may become tilted or oriented in such a way that the filter does not operate as intended. Portions of the filter may become embedded in the vessel wall over time, making retrieval more difficult. While filter retrieval devices are known in the art, improvements can be made to assist in the removal of vena cava filters.